.tool{
    width: 100%;
	height: 100vh;
	background: url("../img/3.jpg") no-repeat;
	background-position: center;
	/* background-attachment: fixed; */
	background-size:cover;  
}
.t_title{
   text-align: center;
   padding: 20px 0;
    font-size:24px;
    font-weight: bolder;
}
.tool_con{
    width:400px;
    height:400px ;
    display: flex;
    margin: 0 auto;
    justify-content: center;
    flex-direction: row;
    flex-wrap: wrap;
}
.item{
    display: block;
    margin-top: 20px;
    width: 100px;
    margin-left: 20px;
    margin-bottom: 20px;
    height: 100px;
    position: relative;
    border-radius: 20px;
    background-color: aqua;
    text-align: center;
    line-height: 100px;
    color: black;
}